Non-Repeating Number Position

             Non-Repeating Number Position

2N+1 numbers are passed as input to the program.
Out of these numbers, N numbers repeat twice and hence account for 2N numbers. Only one number I is a non-repeating number. The program must print the position of the non-repeating number (The position starts from 1).

Note: You need to optimize the logic for large input values. Else "Timeout" will occur.

Input Format:
First line contains N.
Second line contains 2N+1 numbers separated by a space.

Output Format:
First line contains the position of the only non-repeating number I.

Boundary Conditions:

1 <= N <= 1000000
1 <= Value of an individual number <= 9999999

Example Input/Output 1:

Input:
10
86 11 40 10 78 63 73 68 16 44 86 11 40 10 78 73 68 16 24 44 24

Output:
6

Explanation:
N=10, Hence 21 numbers are passed as the input. Among these numbers, only 63 is not repeated. The position of 63 is 6 (As it occurs as the sixth number)

Example Input/Output 2:

Input:
12

7514716 2638298 6854805 6770589 1632983 6032326 6854805 2312182 2312182 367141 9985662 4682266 4682266 6770589 8713485 8964136 8964136 367141 9985662 3099970 1632983 3099970 6032326 8713485 2638298

Output:
1

Explanation:

The only non repeating number is 7514716 which is in the first position.



Code:

#include <bits/stdc++.h>
 using namespace std;
map<long,int>m;
 int main(int argc, char** argv)
{
long long n,sum=0,i,val;
cin>>n;
n=(2*n)+1;
for(i=0;i<n;i++)
{
   cin>>val;
  m[val]=i;
    sum=sum^val;
}
cout<<m[sum]+1;

}